Atomic layer deposition of high density silicon dioxide

ABSTRACT

Atomic layer deposition methods for the low temperature deposition of silicon dioxide films having low nitrogen content and low wet etch rates. Silicon dioxide films are deposited and treated with plasma and re-oxidized resulting in low nitrogen content films.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.62/059,851, filed Oct. 4, 2014, the entire disclosure of which is herebyincorporated by reference herein.

TECHNICAL FIELD

Embodiments of the present disclosure generally relate to methods ofdepositing a silicon oxide film. More particularly, the disclosurerelates to a deposition process for forming a silicon oxide film withlow nitrogen content.

BACKGROUND

The semiconductor industry's tolerance for process variability continuesto decrease as the size of semiconductor devices shrink. To meet thesetighter process requirements, the industry has developed a host of newprocesses which meet the tighter process window requirements, but theseprocesses often take a longer time to complete. For example, for forminga copper diffusion barrier layer conformally onto the surface of a highaspect ratio, 65 nm or smaller interconnect feature, it may be necessaryto use an ALD process. ALD is a variant of CVD that demonstratessuperior step coverage compared to CVD. ALD is based upon atomic layerepitaxy (ALE) that was originally employed to fabricateelectroluminescent displays. ALD employs chemisorption to deposit asaturated monolayer of reactive precursor molecules on a substratesurface. This is achieved by cyclically alternating the pulsing ofappropriate reactive precursors into a deposition chamber. Eachinjection of a reactive precursor is typically separated by an inert gaspurge to provide a new atomic layer to previous deposited layers to forma uniform material layer on the surface of a substrate. Cycles ofreactive precursor and inert purge gases are repeated to form thematerial layer to a desired thickness. The biggest drawback with ALDtechniques is that the deposition rate is much lower than typical CVDtechniques by at least an order of magnitude. For example, some ALDprocesses can require a chamber processing time from about 10 to about200 minutes to deposit a high quality layer on the surface of thesubstrate.

Silicon dioxide is a very important material in the microelectronicsindustry. With the continuation of device miniaturization and increasein the complexity of the device architecture, it becomes verychallenging to deposit highly conformal films over these structures. Inparticular, 3D NAND manufacturing will need highly conformal silicondioxide and silicon nitride deposition inside of holes that have veryhigh aspect ratios. The films need to be similar quality to hightemperature process (>600 C) with a wet etch rate (WER) of about 1 andlow leakage. Many of the future applications in the microelectronicsindustry require the deposition of high quality silicon dioxide films atlow to mid-range temperatures. Accordingly, there is an ongoing need inthe art for methods of uniformly depositing a high quality silicon filmon a substrate in an efficient and cost effective manner.

SUMMARY

Embodiments of the disclosure are directed to processing methods. Asilicon oxide film is deposited on a substrate surface. The siliconoxide film is exposed to a plasma to form a plasma treated silicon oxidefilm. The plasma treated silicon oxide film is exposed to an oxidant todecrease nitrogen content in the plasma treated silicon oxide film toform a low nitrogen content silicon oxide film.

Additional embodiments of the disclosure are directed to processingmethods. A silicon oxide film is deposited on a substrate surface bysequential exposure of the substrate surface to a silicon precursorfollowed by a reactant comprising one or more of oxygen, ozone, water,nitric acid, oxygen plasma or peroxide. The silicon oxide film has ahydrogen content. The silicon oxide film is exposed to a plasmacomprising one or more of hydrogen, nitrogen, argon or nitric oxide toform a plasma treated silicon oxide film with a nitrogen content and alower hydrogen content than the silicon oxide film. The plasma treatedsilicon oxide film is exposed to an oxidant comprising one or more ofoxygen, ozone, water, nitric acid, oxygen plasma or peroxide to decreasenitrogen content in the plasma treated silicon oxide film to form a lownitrogen content silicon oxide film.

Further embodiments of the disclosure are directed to processing methodscomprising placing a substrate having a substrate surface into aprocessing chamber comprising a plurality of sections. Each section isseparated from adjacent sections by a gas curtain. At least a portion ofthe substrate surface is exposed to a first process condition in a firstsection of the processing chamber. The first process condition comprisesa silicon precursor to form a silicon-containing film. The substratesurface is laterally moved through a gas curtain to a second section ofthe processing chamber. The silicon-containing film is exposed to asecond process condition in a second section of the processing chamber.The second process condition comprising a reactant to form a siliconoxide film. The substrate surface is laterally moved with the siliconoxide film through a gas curtain to a third section of the processingchamber. The silicon oxide film is exposed to a plasma to form a plasmatreated silicon oxide film. The substrate surface is moved with theplasma treated silicon oxide film through a gas curtain to a fourthsection of the processing chamber. The plasma treated silicon oxide filmis exposed to an oxidant to form a low nitrogen silicon oxide film.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may admit to otherequally effective embodiments.

FIG. 1 is a cross-sectional side view of a spatial atomic layerdeposition chamber in accordance with one or more embodiment of thedisclosure;

FIG. 2 shows a perspective view of a susceptor in accordance with one ormore embodiments of the disclosure;

FIG. 3 shows a schematic of a pie-shaped gas distribution assembly inaccordance with one or more embodiments of the disclosure;

FIG. 4 is a schematic plan view of a substrate processing systemconfigured with four gas distribution assembly units with a loadingstation in accordance with one or more embodiments of the disclosure;

FIG. 5 is a schematic plan view of a substrate processing systemconfigured with three gas distribution assembly units;

FIG. 6 shows a cross-sectional view of a processing chamber inaccordance with one or more embodiments of the disclosure;

FIG. 7 shows a perspective view of a susceptor assembly and gasdistribution assembly units in accordance with one or more embodimentsof the disclosure;

FIG. 8 shows a cross-sectional view of a processing chamber inaccordance with one or more embodiments of the disclosure;

FIG. 9 shows a schematic of a pie-shaped gas distribution assembly inaccordance with one or more embodiments of the disclosure; and

FIG. 10 shows a graph of the growth per cycle and wet etch rate ratiosfor the samples discussed in the Examples.

DETAILED DESCRIPTION

Some embodiments of the disclosure provide methods of depositing asilicon dioxide films by atomic layer deposition (ALD) in thetemperature range of about 300° C. to about 400° C. Atomic layerdeposition can be performed using a traditional time-domain process or aspatial process. A time-domain process exposes the substrate to a firstprocess gas, purging the process chamber of unreacted first process gasand exposing the substrate to a second process gas. Hence, only oneprocess gas is in the processing chamber at any given time. A spatialALD process, described further below, provides the process gases toseparate parts of a process chamber, maintaining separation of the gasesand moves the substrate through the different parts of the processchamber.

The ALD silicon oxide film of some embodiments is densified with aplasma treatment and the film is reoxidized with an oxygen source.Embodiments of the disclosure provide a high density silicon dioxidefilm with a low wet etch rate (WER) and low leakage at low temperatures.

In some embodiments, a nitrogen plasma treatment is used. Without beingbound by any particular theory of operation, it is believed that thenitrogen ions are able to densify the film and that radicals are able toremove hydrogen from the film through various radical based mechanismsyielding high quality silicon dioxide with low WER. In some embodimentswhere the film being created is not SiN, the removal of Si—N bondsformed removal of the hydrogen from the film is performed.

As used in this specification and the appended claims, the terms“reactive gas”, “precursor”, “reactant”, and the like, are usedinterchangeably to mean a gas that includes a species which is reactivein an atomic layer deposition process. For example, a first “reactivegas” may simply adsorb onto the surface of a substrate and be availablefor further chemical reaction with a second reactive gas.

Embodiments of the disclosure are directed to methods of depositing highquality SiO₂ by ALD at temperatures of 100° C.-650° C. The deposition ofSiO₂ can be carried out by any Si containing precursor (BTBAS, BDEAS,3DMAS, 4DMAS and other silylamines (RR′N)₄SiH_((4-x)), Me₃SiR (R=anyleaving group), and Si(dmap)₄.

It is believed that Me₃SiR is stable up to very high temperatures >650 Csince trimethylsilyl groups on a silicon surface are known to be verystable. Si(dmap)4 should also be very stable since this moleculecontains two of the dmap ligands ligated to the silicon atom in an eta-2fashion. It is well know that chelating ligands are able to add thermalstability to molecules.

The oxygen source during depositions may be O₂, O₃, H₂O, HNO₃, O₂Plasma, and H₂O₂. The plasma source used can be (H₂ Plasma, N₂ Plasma,Ar plasma, N₂O plasma, or mixtures thereof).

Typical deposition experiments follow equation 1, where z is the numberof cycles corresponding to the Si precursor+oxygen source cycles and nis the total number of cycles with the plasma treatment. It is believedthat the additional oxygen source pulse re-oxidizes any Si—X bonds thatmay have formed during the plasma treatment (e.g., if N₂ plasma is usedthan SiN bonds will form). Each pulse is separated by an inert purge orchamber pump or both.[(Si precursor+oxygen source)z+plasma treatment+(oxygensource)y]n  Equation 1.

Alternatively, reactions can follow Equation 2. This process is the sameas that of Equation 1 except that the oxidant used to react with thesilicon precursor can be a different compound than the oxidant.[(Si precursor+reactant)z+plasma treatment+(oxidant)y]n  Equation 2.

Accordingly, one more embodiments of the disclosure are directed toprocessing methods comprising depositing a silicon oxide film on asubstrate surface. In some embodiments, the silicon oxide film isdeposited by atomic layer deposition. In one or more embodiments, thesilicon oxide film is deposited by sequential exposure of the substratesurface a silicon precursor followed by a reactant comprising one ormore of ozone, oxygen, water, nitric acid, oxygen plasma or peroxide.This is the combined (Si precursor+reactant) of Equation 2.

The deposition of the silicon oxide film can occur at any suitabletemperature at which the silicon precursor and reactant are stable. Insome embodiments, the silicon oxide film is deposited at a temperatureless than or equal to about 550° C., or less than or equal to about 500°C., or less than or equal to about 450° C., or less than or equal toabout 400° C., or less than or equal to about 350° C., or less than orequal to about 300° C., or less than or equal to about 250° C., or lessthan or equal to about 200° C., or less than or equal to about 150° C.In some embodiments, the silicon oxide film is deposited at atemperature in the range of about 100° C. to about 400° C.

The silicon oxide film is then exposed to a plasma to form a plasmatreated silicon oxide film. The plasma treated silicon oxide film ofsome embodiments is denser than the silicon oxide film. The plasma ofsome embodiments comprises one or more of hydrogen, nitrogen, argon orN₂O. The plasma can be either a direct plasma or a remote plasma.

In some embodiments, the silicon oxide film has a hydrogen content. Thehydrogen content is decreased with exposure to the plasma. In someembodiments, the plasma treated silicon oxide film has substantially nohydrogen. As used in this specification and the appended claims, theterm “substantially no hydrogen” used in this regard means that hydrogenis present in the film at a concentration less than about 2 atomicpercent, or less than about 1 atomic percent or less than about 0.5atomic percent or less than about 0.1 atomic percent.

After plasma treating the silicon oxide film, atoms of the plasmaspecies may be in the film. For example, a nitrogen plasma may leavenitrogen in the film. The plasma treated silicon oxide film is exposedto an oxidant to decrease the nitrogen content in the film. This forms alow nitrogen content silicon oxide film.

The oxidant used can be the same as the reactant in the ALD depositionof the silicon oxide film or different. In some embodiments the reactantand oxidant are independently selected from the group consisting ofozone, oxygen, water, nitric acid, oxygen plasma, peroxide orcombinations thereof.

In some embodiments, the low nitrogen content silicon oxide film has anitrogen content of less than or equal to about 4 atomic percent, or 3.5atomic percent, or 3 atomic percent or 2.5 atomic percent or 2 atomicpercent. The low nitrogen content silicon oxide film of some embodimentshas a wet etch rate ratio less than about 4, or 3.5, or 3, or 2.5, or 2,or 1.5, or 1.4, or 1.3. The low nitrogen content silicon oxide film ofsome embodiments is grown at a rate greater than about 0.5 Å/cycle, orabout 0.6 Å/cycle, or about 0.7 Å/cycle, or about 0.8 Å/cycle, or about0.9 Å/cycle or about 1.0 Å/cycle or about 1.1 Å/cycle.

As used in this specification and the appended claims, the term“substrate” and “wafer” are used interchangeably, both referring to asurface, or portion of a surface, upon which a process acts. It willalso be understood by those skilled in the art that reference to asubstrate can also refer to only a portion of the substrate, unless thecontext clearly indicates otherwise. For example, in spatially separatedALD, described with respect to FIG. 1, each precursor is delivered tothe substrate, but any individual precursor stream, at any given time,is only delivered to a portion of the substrate. Additionally, referenceto depositing on a substrate can mean both a bare substrate and asubstrate with one or more films or features deposited or formedthereon.

FIG. 1 is a schematic cross-sectional view of a portion of a processingchamber 20 in accordance with one or more embodiments of the disclosure.The processing chamber 20 is generally a sealable enclosure, which isoperated under vacuum, or at least low pressure conditions. The chamber100 includes a gas distribution assembly 30 capable of distributing oneor more gases across the top surface 61 of a substrate 60. The gasdistribution assembly 30 can be any suitable assembly known to thoseskilled in the art, and specific gas distribution assemblies describedshould not be taken as limiting the scope of the disclosure. The outputface of the gas distribution assembly 30 faces the first surface 61 ofthe substrate 60.

Substrates for use with the embodiments of the disclosure can be anysuitable substrate. In some embodiments, the substrate is a rigid,discrete, generally planar substrate. As used in this specification andthe appended claims, the term “discrete” when referring to a substratemeans that the substrate has a fixed dimension. The substrate of one ormore embodiments is a semiconductor substrate, such as a 200 mm or 300mm diameter silicon substrate. In some embodiments, the substrate is oneor more of silicon, silicon germanium, gallium arsenide, galliumnitride, germanium, gallium phosphide, indium phosphide, sapphire andsilicon carbide.

The gas distribution assembly 30 comprises a plurality of gas ports totransmit one or more gas streams to the substrate 60 and a plurality ofvacuum ports disposed between each gas port to transmit the gas streamsout of the processing chamber 20. In the embodiment of FIG. 1, the gasdistribution assembly 30 comprises a first precursor injector 120, asecond precursor injector 130 and a purge gas injector 140. Theinjectors 120, 130, 140 may be controlled by a system computer (notshown), such as a mainframe, or by a chamber-specific controller, suchas a programmable logic controller. The precursor injector 120 injects acontinuous (or pulse) stream of a reactive precursor of compound A intothe processing chamber 20 through a plurality of gas ports 125. Theprecursor injector 130 injects a continuous (or pulse) stream of areactive precursor of compound B into the processing chamber 20 througha plurality of gas ports 135. The purge gas injector 140 injects acontinuous (or pulse) stream of a non-reactive or purge gas into theprocessing chamber 20 through a plurality of gas ports 145. The purgegas removes reactive material and reactive by-products from theprocessing chamber 20. The purge gas is typically an inert gas, such as,nitrogen, argon and helium. Gas ports 145 are disposed in between gasports 125 and gas ports 135 so as to separate the precursor of compoundA from the precursor of compound B, avoiding cross-contamination betweenthe precursors.

In another aspect, a remote plasma source (not shown) may be connectedto the precursor injector 120 and the precursor injector 130 prior toinjecting the precursors into the processing chamber 20. The plasma ofreactive species may be generated by applying an electric field to acompound within the remote plasma source. Any power source that iscapable of activating the intended compounds may be used. For example,power sources using DC, radio frequency (RF), and microwave (MW) baseddischarge techniques may be used. If an RF power source is used, it canbe either capacitively or inductively coupled. The activation may alsobe generated by a thermally based technique, a gas breakdown technique,a high energy light source (e.g., UV energy), or exposure to an x-raysource. Exemplary remote plasma sources are available from vendors suchas MKS Instruments, Inc. and Advanced Energy Industries, Inc.

The chamber 100 further includes a pumping system 150 connected to theprocessing chamber 20. The pumping system 150 is generally configured toevacuate the gas streams out of the processing chamber 20 through one ormore vacuum ports 155. The vacuum ports 155 are disposed between eachgas port so as to evacuate the gas streams out of the processing chamber20 after the gas streams react with the substrate surface and to furtherlimit cross-contamination between the precursors.

The chamber 100 includes a plurality of partitions 160 disposed on theprocessing chamber 20 between each port. A lower portion of eachpartition extends close to the first surface 61 of substrate 60, forexample, about 0.5 mm or greater from the first surface 61. In thismanner, the lower portions of the partitions 160 are separated from thesubstrate surface by a distance sufficient to allow the gas streams toflow around the lower portions toward the vacuum ports 155 after the gasstreams react with the substrate surface. Arrows 198 indicate thedirection of the gas streams. Since the partitions 160 operate as aphysical barrier to the gas streams, they also limit cross-contaminationbetween the precursors. The arrangement shown is merely illustrative andshould not be taken as limiting the scope of the disclosure. It will beunderstood by those skilled in the art that the gas distribution systemshown is merely one possible distribution system and the other types ofshowerheads and gas distribution assemblies may be employed.

Atomic layer deposition systems of this sort (i.e., where multiple gasesare separately flowed toward the substrate at the same time) arereferred to as spatial ALD. In operation, a substrate 60 is delivered(e.g., by a robot) to the processing chamber 20 and can be placed on ashuttle 65 before or after entry into the processing chamber. Theshuttle 65 is moved along the track 70, or some other suitable movementmechanism, through the processing chamber 20, passing beneath (or above)the gas distribution assembly 30. In the embodiment shown in FIG. 1, theshuttle 65 is moved in a linear path through the chamber. FIG. 3, asexplained further below, shows an embodiment in which wafers are movedin a circular path through a carousel processing system.

Referring back to FIG. 1, as the substrate 60 moves through theprocessing chamber 20, the first surface 61 of substrate 60 isrepeatedly exposed to the reactive gas A coming from gas ports 125 andreactive gas B coming from gas ports 135, with the purge gas coming fromgas ports 145 in between. Injection of the purge gas is designed toremove unreacted material from the previous precursor prior to exposingthe substrate surface 110 to the next precursor. After each exposure tothe various gas streams (e.g., the reactive gases or the purge gas), thegas streams are evacuated through the vacuum ports 155 by the pumpingsystem 150. Since a vacuum port may be disposed on both sides of eachgas port, the gas streams are evacuated through the vacuum ports 155 onboth sides. Thus, the gas streams flow from the respective gas portsvertically downward toward the first surface 61 of the substrate 60,across the substrate surface 110 and around the lower portions of thepartitions 160, and finally upward toward the vacuum ports 155. In thismanner, each gas may be uniformly distributed across the substratesurface 110. Arrows 198 indicate the direction of the gas flow.Substrate 60 may also be rotated while being exposed to the various gasstreams. Rotation of the substrate may be useful in preventing theformation of strips in the formed layers. Rotation of the substrate canbe continuous or in discrete steps and can occur while the substrate ispassing beneath the gas distribution assembly 30 or when the substrateis in a region before and/or after the gas distribution assembly 30.

Sufficient space is generally provided after the gas distributionassembly 30 to ensure complete exposure to the last gas port. Once thesubstrate 60 has completely passed beneath the gas distribution assembly30, the first surface 61 has completely been exposed to every gas portin the processing chamber 20. The substrate can then be transported backin the opposite direction or forward. If the substrate 60 moves in theopposite direction, the substrate surface may be exposed again to thereactive gas A, the purge gas, and reactive gas B, in reverse order fromthe first exposure.

The extent to which the substrate surface 110 is exposed to each gas maybe determined by, for example, the flow rates of each gas coming out ofthe gas port and the rate of movement of the substrate 60. In oneembodiment, the flow rates of each gas are controlled so as not toremove adsorbed precursors from the substrate surface 61. The widthbetween each partition, the number of gas ports disposed on theprocessing chamber 20, and the number of times the substrate is passedacross the gas distribution assembly may also determine the extent towhich the substrate surface 61 is exposed to the various gases.Consequently, the quantity and quality of a deposited film may beoptimized by varying the above-referenced factors.

Although description of the process has been made with the gasdistribution assembly 30 directing a flow of gas downward toward asubstrate positioned below the gas distribution assembly, it will beunderstood that this orientation can be different. In some embodiments,the gas distribution assembly 30 directs a flow of gas upward toward asubstrate surface. As used in this specification and the appendedclaims, the term “passed across” means that the substrate has been movedfrom one side of the gas distribution assembly to the other side so thatthe entire surface of the substrate is exposed to each gas stream fromthe gas distribution plate. Absent additional description, the term“passed across” does not imply any particular orientation of gasdistribution assemblies, gas flows or substrate positions.

In some embodiments, the shuttle 65 is a susceptor 66 for carrying thesubstrate 60. Generally, the susceptor 66 is a carrier which helps toform a uniform temperature across the substrate. The susceptor 66 ismovable in both directions (left-to-right and right-to-left, relative tothe arrangement of FIG. 1) or in a circular direction (relative to FIG.3). The susceptor 66 has a top surface 67 for carrying the substrate 60.The susceptor 66 may be a heated susceptor so that the substrate 60 maybe heated for processing. As an example, the susceptor 66 may be heatedby radiant heat lamps 90, a heating plate, resistive coils, or otherheating devices, disposed underneath the susceptor 66.

In still another embodiment, the top surface 67 of the susceptor 66includes a recess 68 to accept the substrate 60, as shown in FIG. 2. Thesusceptor 66 is generally thicker than the thickness of the substrate sothat there is susceptor material beneath the substrate. In someembodiments, the recess 68 is sized such that when the substrate 60 isdisposed inside the recess 68, the first surface 61 of substrate 60 islevel with, or substantially coplanar with, the top surface 67 of thesusceptor 66. Stated differently, the recess 68 of some embodiments issized such that when a substrate 60 is disposed therein, the firstsurface 61 of the substrate 60 does not protrude above the top surface67 of the susceptor 66. As used in this specification and the appendedclaims, the term “substantially coplanar” means that the top surface ofthe wafer and the top surface of the susceptor assembly are coplanarwithin ±0.2 mm. In some embodiments, the top surfaces are coplanarwithin ±0.15 mm, ±0.10 mm or ±0.05 mm.

FIG. 1 shows a cross-sectional view of a processing chamber in which theindividual gas ports are shown. This embodiment can be either a linearprocessing system in which the width of the individual gas ports issubstantially the same across the entire width of the gas distributionplate, or a pie-shaped segment in which the individual gas ports changewidth to conform to the pie shape. FIG. 3 shows a portion of apie-shaped gas distribution assembly 30. A substrate would be passedacross this gas distribution assembly 30 in an arc shape path 32. Eachof the individual gas ports 125, 135, 145, 155 have a narrower widthnear the inner peripheral edge 33 of the gas distribution assembly 30 aand a larger width near the outer peripheral edge 34 of the gasdistribution assembly 30. The shape or aspect ratio of the individualports can be proportional to, or different from, the shape or aspectratio of the gas distribution assembly 30 segment. In some embodiments,the individual ports are shaped so that each point of a wafer passingacross the gas distribution assembly 30 following path 32 would haveabout the same residence time under each gas port. The path of thesubstrates can be perpendicular to the gas ports. In some embodiments,each of the gas distribution assemblies comprise a plurality of elongategas ports which extend in a direction substantially perpendicular to thepath traversed by a substrate. As used in this specification and theappended claims, the term “substantially perpendicular” means that thegeneral direction of movement is approximately perpendicular to the axisof the gas ports. For a pie-shaped gas port, the axis of the gas portcan be considered to be a line defined as the mid-point of the width ofthe port extending along the length of the port. As described furtherbelow, each of the individual pie-shaped segments can be configured todeliver a single reactive gas or multiple reactive gases separatedspatially or in combination (e.g., as in a typical CVD process).

Processing chambers having multiple gas injectors can be used to processmultiple wafers simultaneously so that the wafers experience the sameprocess flow. For example, as shown in FIG. 4, the processing chamber100 has four gas distribution assemblies 30 and four substrates 60. Atthe outset of processing, the substrates 60 can be positioned betweenthe distribution assemblies 30. Rotating the susceptor 66 of thecarousel by 45° will result in each substrate 60 being moved to aninjector assembly 30 for film deposition. This is the position shown inFIG. 4. An additional 45° rotation would move the substrates 60 awayfrom the distribution assemblies 30. With spatial ALD injectors, a filmis deposited on the wafer during movement of the wafer relative to theinjector assembly. In some embodiments, the susceptor 66 is rotated sothat the substrates 60 do not stop beneath the distribution assemblies30. The number of substrates 60 and gas distribution assemblies 30 canbe the same or different. In some embodiments, there is the same numberof wafers being processed as there are gas distribution assemblies. Inone or more embodiments, the number of wafers being processed are aninteger multiple of the number of gas distribution assemblies. Forexample, if there are four gas distribution assemblies, there are 4×wafers being processed, where x is an integer value greater than orequal to one.

The processing chamber 100 shown in FIG. 4 is merely representative ofone possible configuration and should not be taken as limiting the scopeof the disclosure. Here, the processing chamber 100 includes a pluralityof gas distribution assemblies 30. In the embodiment shown, there arefour gas distribution assemblies 30 evenly spaced about the processingchamber 100. The processing chamber 100 shown is octagonal, however, itwill be understood by those skilled in the art that this is one possibleshape and should not be taken as limiting the scope of the disclosure.The gas distribution assemblies 30 shown are rectangular, but it will beunderstood by those skilled in the art that the gas distributionassemblies can be pie-shaped segments, like that shown in FIG. 3.Additionally, each segment can be configured to deliver gases in aspatial type arrangement with multiple different reactive gases flowingfrom the same segment or configured to deliver a single reactive gas ora mixture of reactive gases.

The processing chamber 100 includes a substrate support apparatus, shownas a round susceptor 66 or susceptor assembly. The substrate supportapparatus, or susceptor 66, is capable of moving a plurality ofsubstrates 60 beneath each of the gas distribution assemblies 30. A loadlock 82 might be connected to a side of the processing chamber 100 toallow the substrates 60 to be loaded/unloaded from the chamber 100.

The processing chamber 100 may include a plurality, or set, of firsttreatment stations 80 positioned between any or each of the plurality ofgas distribution assemblies 30. In some embodiments, each of the firsttreatment stations 80 provides the same treatment to a substrate 60.

The number of treatment stations and the number of different types oftreatment stations can vary depending on the process. For example, therecan be one, two, three, four, five, six, seven or more treatmentstations positioned between the gas distribution assemblies 30. Eachtreatment stations can independently provide a different treatment fromevery other set of treatments station, or there can be a mixture of thesame type and different types of treatments. In some embodiments, one ormore of the individual treatments stations provides a differenttreatment than one or more of the other individual treatment stations.The embodiment shown in FIG. 4 shows four gas distribution assemblieswith spaces between which can include some type of treatment station.However, it can be easily envisioned from this drawing that theprocessing chamber can readily be incorporated with eight gasdistribution assemblies with the gas curtains between.

In the embodiment shown in FIG. 5, a set of second treatment stations 85are positioned between the first treatment stations 80 and the gasdistribution assemblies 30 so that a substrate 60 rotated through theprocessing chamber 100 would encounter, depending on where the substrate60 starts, a gas distribution assembly 30, a first treatment station 80and a second treatment station 85 before encountering a second of any ofthese. For example, as shown in FIG. 5, if the substrate started at thefirst treatment station 80, it would see, in order, the first treatmentstation 80, a gas distribution assembly 30 and a second treatmentstation 85 before encountering a second first treatment station 85.

Treatment stations can provide any suitable type of treatment to thesubstrate, film on the substrate or susceptor assembly. For example, UVlamps, flash lamps, plasma sources and heaters. The wafers are thenmoved between positions with the gas distribution assemblies 30 to aposition with, for example, a showerhead delivering plasma to the wafer.The plasma station being referred to as a treatment station 80. In oneor more example, silicon nitride films can be formed with plasmatreatment after each deposition layer. As the ALD reaction is,theoretically, self-limiting as long as the surface is saturated,additional exposure to the deposition gas will not cause damage to thefilm.

Rotation of the carousel can be continuous or discontinuous. Incontinuous processing, the wafers are constantly rotating so that theyare exposed to each of the injectors in turn. In discontinuousprocessing, the wafers can be moved to the injector region and stopped,and then to the region 84 between the injectors and stopped. Forexample, the carousel can rotate so that the wafers move from aninter-injector region across the injector (or stop adjacent theinjector) and on to the next inter-injector region where it can pauseagain. Pausing between the injectors may provide time for additionalprocessing steps between each layer deposition (e.g., exposure toplasma).

In some embodiments, the processing chamber comprises a plurality of gascurtains 40. Each gas curtain 40 creates a barrier to prevent, orminimize, the movement of processing gases from the gas distributionassemblies 30 from migrating from the gas distribution assembly regionsand gases from the treatment stations 80 from migrating from thetreatment station regions. The gas curtain 40 can include any suitablecombination of gas and vacuum streams which can isolate the individualprocessing sections from the adjacent sections. In some embodiments, thegas curtain 40 is a purge (or inert) gas stream. In one or moreembodiments, the gas curtain 40 is a vacuum stream that removes gasesfrom the processing chamber. In some embodiments, the gas curtain 40 isa combination of purge gas and vacuum streams so that there are, inorder, a purge gas stream, a vacuum stream and a purge gas stream. Inone or more embodiments, the gas curtain 40 is a combination of vacuumstreams and purge gas streams so that there are, in order, a vacuumstream, a purge gas stream and a vacuum stream. The gas curtains 40shown in FIG. 4 are positioned between each of the gas distributionassemblies 30 and treatment stations 80, but it will be understood thatthe curtains can be positioned at any point or points along theprocessing path.

FIG. 6 shows an embodiment of a processing chamber 200 including a gasdistribution assembly 220, also referred to as the injectors, and asusceptor assembly 230. In this embodiment, the susceptor assembly 230is a rigid body. The rigid body of some embodiments has a drooptolerance no larger than 0.05 mm. Actuators 232 are placed, for example,at three locations at the outer diameter region of the susceptorassembly 230. As used in this specification and the appended claims, theterms “outer diameter” and “inner diameter” refer to regions near theouter peripheral edge and the inner edge, respectively. The outerdiameter is not to a specific position at the extreme outer edge (e.g.,near shaft 240) of the susceptor assembly 230, but is a region near theouter edge 231 of the susceptor assembly 230. This can be seen in FIG. 6from the placement of the actuators 232. The number of actuators 232 canvary from one to any number that will fit within the physical spaceavailable. Some embodiments have two, three, four or five sets ofactuators 232 positioned in the outer diameter region 231. As used inthis specification and the appended claims, the term “actuator” refersto any single or multi-component mechanism which is capable of movingthe susceptor assembly 230, or a portion of the susceptor assembly 230,toward or away from the gas distribution assembly 220. For example,actuators 232 can be used to ensure that the susceptor assembly 230 issubstantially parallel to the injector assembly 220. As used in thisspecification and the appended claims, the term “substantially parallel”used in this regard means that the parallelism of the components doesnot vary by more than 5% relative to the distance between thecomponents.

Once pressure is applied to the susceptor assembly 230 from theactuators 232, the susceptor assembly 230 can be levelled. As thepressure is applied by the actuators 232, the gap 210 distance can beset to be within the range of about 0.1 mm to about 2.0 mm, or in therange of about 0.2 mm to about 1.8 mm, or in the range of about 0.3 mmto about 1.7 mm, or in the range of about 0.4 mm to about 1.6 mm, or inthe range of about 0.5 mm to about 1.5 mm, or in the range of about 0.6mm to about 1.4 mm, or in the range of about 0.7 mm to about 1.3 mm, orin the range of about 0.8 mm to about 1.2 mm, or in the range of about0.9 mm to about 1.1 mm, or about 1 mm.

The susceptor assembly 230 is positioned beneath the gas distributionassembly 220. The susceptor assembly 230 includes a top surface 241 and,optionally, at least one recess 243 in the top surface 241. The recess243 can be any suitable shape and size depending on the shape and sizeof the wafers 260 being processed. In the embodiment shown, the recess243 has a step region around the outer peripheral edge of the recess241. The steps can be sized to support the outer peripheral edge of thewafer 260. The amount of the outer peripheral edge of the wafer 260 thatis supported by the steps can vary depending on, for example, thethickness of the wafer and the presence of features already present onthe back side of the wafer.

In some embodiments, as shown in FIG. 6, the recess 243 in the topsurface 241 of the susceptor assembly 230 is sized so that a wafer 260supported in the recess 243 has a top surface 261 substantially coplanarwith the top surface 241 of the susceptor assembly 230. As used in thisspecification and the appended claims, the term “substantially coplanar”means that the top surface of the wafer and the top surface of thesusceptor assembly are coplanar within ±0.2 mm. In some embodiments, thetop surfaces are coplanar within ±0.15 mm, ±0.10 mm or ±0.05 mm.

The susceptor assembly 230 of FIG. 6 includes a support post 240 whichis capable of lifting, lowering and rotating the susceptor assembly 230.The susceptor assembly 230 may include a heater, or gas lines, orelectrical components within the center of the support post 240. Thesupport post 240 may be the primary means of increasing or decreasingthe gap between the susceptor assembly 230 and the gas distributionassembly 220, moving the susceptor assembly 230 into rough position. Theactuators 232 can then make micro-adjustments to the position of thesusceptor assembly to create the desired gap.

The processing chamber 100 shown in FIG. 6 is a carousel-type chamber inwhich the susceptor assembly 230 can hold a plurality of wafers 260. Thegas distribution assembly 220 may include a plurality of separateinjector units 221, each injector unit 221 being capable of depositing afilm or part of a film on the wafer 260, as the wafer is moved beneaththe injector unit 221. FIG. 7 shows a perspective view of acarousel-type processing chamber 200. Two pie-shaped injector units 221are shown positioned on approximately opposite sides of and above thesusceptor assembly 230. This number of injector units 221 is shown forillustrative purposes only. It will be understood that more or lessinjector units 221 can be included. In some embodiments, there are asufficient number of pie-shaped injector units 221 to form a shapeconforming to the shape of the susceptor assembly 230. In someembodiments, each of the individual pie-shaped injector units 221 may beindependently moved, removed and/or replaced without affecting any ofthe other injector units 221. For example, one segment may be raised topermit a robot to access the region between the susceptor assembly 230and gas distribution assembly 220 to load/unload wafers 260.

FIG. 8 shows another embodiment of the disclosure in which the susceptorassembly 230 is not a rigid body. In some embodiments, the susceptorassembly 230 has a droop tolerance of not more than about 0.1 mm, or notmore than about 0.05 mm, or not more than about 0.025 mm, or not morethan about 0.01 mm. Here, there are actuators 232 placed at the outerdiameter region 231 and at the inner diameter region 239 of thesusceptor assembly 230. The actuators 232 can be positioned at anysuitable number of places around the inner and outer periphery of thesusceptor assembly 230. In some embodiments, the actuators 232 areplaced at three locations at both the outer diameter region 231 and theinner diameter region 239. The actuators 232 at both the outer diameterregion 231 and the inner diameter region 239 apply pressure to thesusceptor assembly 230.

FIG. 9 shows an embodiment of a processing chamber comprising a circulargas distribution assembly with a diverter and a susceptor assembly. Thecircular gas distribution assembly 220, a portion of which can be seenin FIG. 9 is positioned within the processing chamber and comprises aplurality of elongate gas ports 125, 135, 145 in a front face 225 of thegas distribution assembly 220. The plurality of elongate gas ports 125,135, 145 extend from an area adjacent the inner peripheral edge 227toward an area adjacent the outer peripheral edge 228 of the gasdistribution assembly 220. The plurality of gas ports shown in FIG. 9include a first reactive gas port 125, a second reactive gas port 135, apurge gas port 145 which surrounds each of the first reactive gas portsand the second reactive gas ports and vacuum ports 155.

A susceptor assembly 230 is positioned within the processing chamber torotate at least one substrate in a substantially circular path about arotational axis. As used in this specification and the appended claims,the term “substantially circular” means that the path is intended to becircular if the substrate were to complete a full rotation. Thesusceptor assembly has a top surface 241 (as shown in FIG. 8) defined byan inner peripheral edge 229 and an outer peripheral edge 231. Thesusceptor assembly 230 is positioned below the gas distribution assembly220 so that the top surface 241 of the susceptor assembly 230 faces thefront face 225 of the gas distribution assembly 220.

Some embodiments of the disclosure are directed to methods of processinga substrate. A substrate is placed into a processing chamber which has aplurality of sections, with each section separated from adjacentsections by a gas curtain. As used in this specification and theappended claims, the terms “section”, “region” and “sector” are usedinterchangeably to describe an area within a batch processing chamber.Upon entering the processing chamber, the substrate (also called awafer) can be in any of the individual sections. Each section can havethe same or different processing conditions from the adjacent sections.As used in this specification and the appended claims, the term“processing condition,” and the like, means the entirety of theconditions within the individual section. For example, processingconditions include, but are not limited to, gas composition, pressure,flow rate, temperature and plasma. Processing conditions can beconfigured to, for example, deposition, etching and treatment (e.g.,densification, annealing).

In the first section, the substrate, or a portion of the substrate, isexposed to a first process condition to deposit a first film on thesurface of the substrate. The substrate surface can be a bare substratesurface or any layer previously deposited on the surface. The individualsurface composition can vary and should not be taken as limiting thescope of the disclosure. In some embodiments, the first processconditions in the first section comprise a silicon-containing precursor.The silicon-containing precursor adsorbs (or similar mechanism) to thesubstrate surface forming a silicon-containing film.

After formation of the silicon-containing film, the substrate islaterally moved through a gas curtain to a second section of theprocessing chamber. In the second section, the silicon-containing filmis exposed to second process conditions to form a second film. Thesecond process conditions comprise a reactant that can react with thesilicon-containing film to form a silicon oxide film.

During the movement from the first section to the second section, thesubstrate is exposed to the first process conditions, the second processconditions and a gas curtain which separates the two. The gas curtaincan be, for example, a combination of inert gases and vacuum to ensurethat there is minimal, if any, gas phase reaction between the firstprocess conditions and the second process conditions. At some timeduring the movement, part of the surface is exposed to the first processconditions, another part of the surface is exposed to the second processconditions and an intermediate portion, between the other two portions,of the substrate is exposed to the gas curtain.

The exposure to the first process conditions and the second processconditions can be repeated sequentially to grow a film of predeterminedthickness. For example, the batch processing chamber may contain twosections with the first process conditions and two sections of thesecond process conditions in alternating pattern, so that rotation ofthe substrate around the central axis of the processing chamber causesthe surface to be sequentially and repeatedly exposed to the first andsecond process conditions so that each exposure causes the filmthickness (for depositions) to grow.

The substrate is moved laterally from the second section through a gascurtain to a third section of the processing chamber. The third sectionhas third process conditions comprising a plasma. The silicon oxide filmis exposed to the plasma to form a plasma treated silicon oxide film.During transfer, a first portion of the surface is exposed to the secondprocess conditions at the same time that a second portion of the surfaceis exposed to the third process conditions and an intermediate portionof the substrate is exposed to the gas curtain. As used in thisspecification and the appended claims, the term “intermediate portion”used in this respect means a portion of the substrate between the firstportion with is exposed to one process condition and the second portionwhich is exposed to a different process condition.

The substrate is laterally moved from the third section through a gascurtain to a fourth section of the processing chamber. The plasmatreated silicon oxide film is exposed to fourth process conditions toform a low nitrogen silicon oxide film. The fourth process conditionscomprise an oxidant. During movement, a first portion of the surface isexposed to the third process conditions at the same time that a secondportion of the surface is exposed to the fourth process conditions andan intermediate portion of the surface is exposed to the gas curtain.

The direction of motion of the substrate can be unidirectional orreciprocal. As used in this context, unidirectional means that thesubstrate is moved in one direction on the macro scale. For example, thesubstrate may be rotated clockwise around the processing chamber buthave small portions that are counter-clockwise. If the overall directionof motion is clockwise, then the movement is unidirectional. The samewould be the case if the motion were counter-clockwise with periodicclockwise rotation. In an embodiment of this sort, the substrate can belaterally moved from the fourth section of the processing chamber to thefirst section of the processing chamber without exposure to either thesecond section or the third section. In one or more embodiments, thesubstrate is moved from the fourth section directly to the first sectionand the exposure to the first process condition; second processcondition; third process condition and fourth process condition arerepeated. This can be done any number of times to deposit a film ofdesired thickness.

In some embodiments, the direction of rotation is reciprocal on themacro scale. This means that the overall motion would be clockwisethrough all sections and then reversed to be counter-clockwise throughall sections of the processing chamber. In one or more embodiments, themotion is a combination of unidirectional and reciprocal. For example,the substrate may be moved in a single direction through the firstsection of the processing chamber and then moved in a reciprocal motionback and forth in the second section or, for example, between the secondand third sections before moving onto the fourth section. Those skilledin the art will understand that there are any numbers of individualrotation/motion patterns available.

EXAMPLES Example 1

Si precursor was Me₃Si(pyrrolyl) (2 s exposure); oxygen source was O₃ (3s exposure); plasma treatment was a N₂ Plasma (100 W) (5 s exposure);referring to Equation 1, z=4, y=0, n=100 cycles; Deposition temperaturewas 300 C.

Example 2

Si precursor was Me₃Si(pyrrolyl) (2 s exposure); oxygen source was O₃ (3s exposure); plasma treatment was a N₂ Plasma (100 W) (5 s exposure);referring to Equation 1, z=4, y=0, n=100 cycles; Deposition temperaturewas 400 C.

Example 3

Si precursor was Me₃Si(pyrrolyl) (2 s exposure) oxygen source=Ozone (6 sexposure); plasma treatment was N₂ Plasma (100 W) (5 s exposure);referring to Equation 1, y=1 z=1 n=100 cycles Deposition temperature was300 C.

Example 4

Si precursor was Me₃Si(pyrrolyl) (2 s exposure) oxygen source=Ozone (6 sexposure); plasma treatment was N₂ Plasma (100 W) (5 s exposure);referring to Equation 1, y=1 z=1 n=100 cycles; Deposition temperaturewas 400 C.

Example 5

Si precursor was Me₃Si(pyrrolyl) (2 s exposure) oxygen source=Ozone (3 sexposure) plasma treatment was a N₂ Plasma (100 W) (5 s exposure);referring to Equation 1, y=0 z=1 n=100 cycles; Deposition temperaturewas 400 C.

The inventors have found that a silicon oxide film can be deposited atlow temperatures with compositions that are almost 100% SiO₂, and have aWERR as low as 1.5 when combining an ozone process with periodic N₂plasma treatments. Without being bound by any particular theory ofoperation, it is believed that the improvement in film properties isrelated to the N₂ or N radicals extracting hydrogen out of the filmthrough various radical mechanisms.

In some embodiments, one or more layers may be formed during a plasmaenhanced atomic layer deposition (PEALD) process. In some processes, theuse of plasma provides sufficient energy to promote a species into theexcited state where surface reactions become favorable and likely.Introducing the plasma into the process can be continuous or pulsed. Insome embodiments, sequential pulses of precursors (or reactive gases)and plasma are used to process a layer. In some embodiments, thereagents may be ionized either locally (i.e., within the processingarea) or remotely (i.e., outside the processing area). In someembodiments, remote ionization can occur upstream of the depositionchamber such that ions or other energetic or light emitting species arenot in direct contact with the depositing film. In some PEALD processes,the plasma is generated external from the processing chamber, such as bya remote plasma generator system. The plasma may be generated via anysuitable plasma generation process or technique known to those skilledin the art. For example, plasma may be generated by one or more of amicrowave (MW) frequency generator or a radio frequency (RF) generator.The frequency of the plasma may be tuned depending on the specificreactive species being used. Suitable frequencies include, but are notlimited to, 2 MHz, 13.56 MHz, 40 MHz, 60 MHz and 100 MHz. Althoughplasmas may be used during the deposition processes disclosed herein, itshould be noted that plasmas may not be required. Indeed, otherembodiments relate to deposition processes under very mild conditionswithout a plasma.

According to one or more embodiments, the substrate is subjected toprocessing prior to and/or after forming the layer. This processing canbe performed in the same chamber or in one or more separate processingchambers. In some embodiments, the substrate is moved from the firstchamber to a separate, second chamber for further processing. Thesubstrate can be moved directly from the first chamber to the separateprocessing chamber, or it can be moved from the first chamber to one ormore transfer chambers, and then moved to the desired separateprocessing chamber. Accordingly, the processing apparatus may comprisemultiple chambers in communication with a transfer station. An apparatusof this sort may be referred to as a “cluster tool” or “clusteredsystem”, and the like.

Generally, a cluster tool is a modular system comprising multiplechambers which perform various functions including substratecenter-finding and orientation, degassing, annealing, deposition and/oretching. According to one or more embodiments, a cluster tool includesat least a first chamber and a central transfer chamber. The centraltransfer chamber may house a robot that can shuttle substrates betweenand among processing chambers and load lock chambers. The transferchamber is typically maintained at a vacuum condition and provides anintermediate stage for shuttling substrates from one chamber to anotherand/or to a load lock chamber positioned at a front end of the clustertool. Two well-known cluster tools which may be adapted for the presentdisclosure are the Centura® and the Endura®, both available from AppliedMaterials, Inc., of Santa Clara, Calif. However, the exact arrangementand combination of chambers may be altered for purposes of performingspecific steps of a process as described herein. Other processingchambers which may be used include, but are not limited to, cyclicallayer deposition (CLD), atomic layer deposition (ALD), chemical vapordeposition (CVD), physical vapor deposition (PVD), etch, pre-clean,chemical clean, thermal treatment such as RTP, plasma nitridation,degas, orientation, hydroxylation and other substrate processes. Bycarrying out processes in a chamber on a cluster tool, surfacecontamination of the substrate with atmospheric impurities can beavoided without oxidation prior to depositing a subsequent film.

According to one or more embodiments, the substrate is continuouslyunder vacuum or “load lock” conditions, and is not exposed to ambientair when being moved from one chamber to the next. The transfer chambersare thus under vacuum and are “pumped down” under vacuum pressure. Inertgases may be present in the processing chambers or the transferchambers. In some embodiments, an inert gas is used as a purge gas toremove some or all of the reactants after forming the layer on thesurface of the substrate. According to one or more embodiments, a purgegas is injected at the exit of the deposition chamber to preventreactants from moving from the deposition chamber to the transferchamber and/or additional processing chamber. Thus, the flow of inertgas forms a curtain at the exit of the chamber.

During processing, the substrate can be heated or cooled. Such heatingor cooling can be accomplished by any suitable means including, but notlimited to, changing the temperature of the substrate support (e.g.,susceptor) and flowing heated or cooled gases to the substrate surface.In some embodiments, the substrate support includes a heater/coolerwhich can be controlled to change the substrate temperatureconductively. In one or more embodiments, the gases (either reactivegases or inert gases) being employed are heated or cooled to locallychange the substrate temperature. In some embodiments, a heater/cooleris positioned within the chamber adjacent the substrate surface toconvectively change the substrate temperature.

The substrate can also be stationary or rotated during processing. Arotating substrate can be rotated continuously or in discreet steps. Forexample, a substrate may be rotated throughout the entire process, orthe substrate can be rotated by a small amount between exposures todifferent reactive or purge gases. Rotating the substrate duringprocessing (either continuously or in steps) may help produce a moreuniform deposition or etch by minimizing the effect of, for example,local variability in gas flow geometries.

While the foregoing is directed to embodiments of the presentdisclosure, other and further embodiments of the disclosure may bedevised without departing from the basic scope thereof, and the scopethereof is determined by the claims that follow.

What is claimed is:
 1. A processing method comprising: depositing asilicon oxide film on a substrate surface at a temperature of about 300°C. to about 400° C. by sequential exposure of the substrate surface to asilicon precursor followed by a reactant comprising one or more ofoxygen, ozone, water, nitric acid, oxygen plasma or peroxide, thesilicon oxide film having a hydrogen content; exposing the silicon oxidefilm to a plasma comprising nitrogen to form a plasma treated siliconoxide film with a nitrogen content greater than or equal to 2.5 atomicpercent and a lower hydrogen content than the silicon oxide film; andexposing the plasma treated silicon oxide film to an oxidant comprisingozone to decrease nitrogen content in the plasma treated silicon oxidefilm to form a low nitrogen content silicon oxide film with a nitrogencontent less than 2.5 atomic percent.
 2. A processing method comprising:placing a substrate having a substrate surface into a processing chambercomprising a plurality of sections, each section separated from adjacentsections by a gas curtain; exposing at least a portion of the substratesurface to a first process condition in a first section of theprocessing chamber, the first process condition comprising a siliconprecursor to form a silicon-containing film; laterally moving thesubstrate surface through a gas curtain to a second section of theprocessing chamber; exposing the silicon-containing film to a secondprocess condition in a second section of the processing chamber, thesecond process condition comprising a reactant to form a silicon oxidefilm, the silicon oxide film having a nitrogen content greater than orequal to 2.5 atomic percent; laterally moving the substrate surface withthe silicon oxide film through a gas curtain to a third section of theprocessing chamber; exposing the silicon oxide film to a plasma to forma plasma treated silicon oxide film; laterally moving the substratesurface with the plasma treated silicon oxide film through a gas curtainto a fourth section of the processing chamber; and exposing the plasmatreated silicon oxide film to an oxidant to lower the nitrogen contentto form a low nitrogen silicon oxide film with a nitrogen content lessthan or equal to 2.5 atomic percent, wherein the oxidant does notcontain plasma.
 3. The processing method of claim 2, wherein thereactant and the oxidant are independently selected from the groupconsisting of ozone, oxygen, water, nitric acid, oxygen plasma, peroxideor combinations thereof.
 4. The processing method of claim 2, whereinthe silicon oxide film is deposited at a temperature in the range ofabout 100° C. to about 400° C.
 5. The processing method of claim 2,wherein the plasma comprises one or more of hydrogen, nitrogen, argon orN₂O.
 6. The processing method of claim 5, wherein the plasma is a remoteplasma.